How would our species evolve in space? If humanity suddenly had to abandon Earth on a fleet of space-arks, we would probably go extinct before evolution by natural selection had time to alter our bodies to cope with the new environment.
Even if we assume that air, food and water could all be synthesised and recycled indefinitely, a microgravity environment currently causes astronauts aboard the International Space Station to lose about one per cent of their bone density each month, even with strenuous daily workouts.
After a few years of this, everyone would be suffering from severe osteoporosis. If our voyage took us into deep space, we would also need to worry about radiation. Galactic cosmic rays would bathe us in roughly 250 times the normal background radiation we receive on Earth and a single solar flare could be strong enough to cause radiation poisoning.
In order to survive this for decades at a time, we would need spaceships with more Earth-like environments than current spacecraft have. Large-diameter rotating habitats to simulate gravity and thick shielding to block the radiation would be the bare minimum. But if conditions on the spacecraft are just like Earth, there would be no evolutionary pressure to cause our bodies to adapt.
Society would certainly evolve though. Surrounded by danger and acutely dependent on technology, we might develop much more authoritarian societies where each person must perform their allocated role without question and be ready to sacrifice themselves for the benefit of the species. This would be too important to leave to the unpredictability of democratic, free-market capitalism, so perhaps a rigid hierarchy, akin to the regimes aboard 19th century sailing ships would emerge.
Read more:
- Has anybody had sex in space?
- How to grow food in space: the Antarctic base preparing for human space colonies
- Elisa Raffaella Ferrè: What happens to the brain in space?
- Living at low gravity could alter your DNA, suggests study of worms in space
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Asked by: Sophie, via email
